Doctors in Southern California have implanted counterfeit screws and rods, ginned up in a small machine shop, into the backs of thousands of injured workers, according to lawsuits filed throughout the state.

Some doctors who used the bogus hardware took kickbacks including cash and private plane rides, while middlemen and hospitals profited by wildly inflating the cost of the screws, according to one suit filed in Sacramento.

The allegations deepen the scandal surrounding a Corona del Mar hospital executive who pleaded guilty in April to paying doctors to bring in patients as part of a $500 million insurance scam.

The executive, Michael Drobot, also admitted to bribing former state Sen. Ronald Calderon to keep huge insurance payments flowing.

The latest lawsuit, filed in mid-June in Los Angeles, says the knockoff spinal implants could harm patients because they could get an infection or react to metal that is not surgical grade. The screws also might loosen or fail. Some of the bogus screws cost $300 to make but were billed at as much as $12,500 each, records say.

“It’s probably the worst example where fraud has progressed from being a financial crime to hurting people for profit,” said Thomas Fraysse, an Oakland attorney on the case. “It’s beyond unethical.”

Law firms in the Bay Area and Los Angeles plan to continue to file cases on behalf of people with counterfeit implants studding their backs.

A contractor for Spinal Solutions, the firm accused of distributing the implants, and an attorney for the machine shop’s owner deny the allegations, saying it is impossible that the elderly machinist mass-produced the hardware.

The cases revolve around spinal fusion surgeries, in which rods and screws are implanted in the back to relieve pain. The state’s workers’ compensation system long paid a premium for hardware used in the surgeries until a loophole was closed by recent legislation.

The latest lawsuit accuses defendants of fraud and battery, saying the hardware has put the life of the patient, Arthur Golia of Riverside, at risk. Golia had seven counterfeit devices implanted in his spine, according to the suit.

It follows a similar January case, which alleges that a Los Angeles man had medical implants from the mom-and-pop machine shop in Temecula put in his back in 2011. One of the screws broke, requiring David Solomon to undergo a second surgery in 2013. He has ongoing pain and loss of movement, the lawsuit says.

“If you break this down to the core of right and wrong, it really is using people as pieces of meat to make money,” said Santa Ana attorney Chris Purcell, who filed the Solomon case in Los Angeles Superior Court. “It’s horrifying to me that this could still happen in this day and age.”

A separate whistleblower lawsuit alleges that many of the patients with fake implants may not have needed the surgery at all. According to that May 2012 suit, they were the collateral damage of a massive scheme to defraud insurers, involving Drobot, former owner of Pacific Hospital of Long Beach.